There has been known pulmonary embolism in which a thrombus formed in a vein in a lower limb or the like is moved by a bloodstream into a pulmonary artery and the bloodstream in the pulmonary artery is inhibited by the thrombus. As a treating method for the pulmonary embolism, conventionally, there has been adopted a method of administering a drug such as an anticoagulant and a thrombolytic agent (see Japanese Translations of PCT for Patent No. 2011-510933), or a method of implanting a thrombus filter or the like at the stage of confirmation of the presence of a thrombus in a vein in a lower limb (see Japanese Patent Laid-Open No. 2001-259025).
However, the therapeutic method of using a drug can be disadvantageous in that it can take time for the effect of the administered drug to appear. According to the method of using a thrombus filter, for example, it can be necessary to accurately grasp the position where the thrombus is present, prior to the onset of pulmonary embolism. By these methods, therefore, it may be impossible to adequately cope with a serious emergency patient abruptly suffering pulmonary embolism, and, depending on the patient's condition, it may be impossible to produce a substantial therapeutic effect.
Accordingly, a medical instrument is disclosed which can speedily crush a thrombus present in a pulmonary artery and thereby can obtain a substantial therapeutic effect on pulmonary embolism.